"We all want to be happy, but we can't stop screwing each other over."

What is the one thing that all these conversations are about? Happiness, probably, or maybe fate. Or maybe how fate determines our happiness, and there's not a darn thing we can do about it.

This interesting, multi-storied film, written by sisters Karen and Jill Sprecher and directed by Karen, has introspective things like that on its mind, but it is no sit-around-and-talk angst-fest. No, the disparate New Yorkers here are out DOING things -- often to each other, though they don't know it, because they don't know each other.

First we meet Walker (John Turturro), a nebbish physics professor who tells his passive wife (Amy Irving) what he wants is "to be enthused, to be happy." A while back, he was mugged and got a black eye. Since then, he can't seem to cope. Also, he is having an affair, though it's not making him any happier.

Then there's a hotshot lawyer, Troy (Matthew McConaughey, doing a cockier version of his "A Time to Kill" character), celebrating another victory in which he has sent a guilty man to jail. He doesn't believe in fate or luck; "luck is a lazy man's excuse," he says. People need to accept responsibility for their actions, that's his motto. Then, in a bit of "Twilight Zone"-style karma, he hits a pedestrian, assumes she is dead, and flees the scene. He is subsequently racked with guilt.

Troy had talked with a man in a bar, Gene English (Alan Arkin), whose son is a delinquent (Troy will have dealings with him) and whose ex-wife is a pain. Gene is bitter and cynical. Seems not long ago, a cheerful co-worker hit the lottery, only to find being rich just made his life worse. Which doesn't seem to stop Gene from being jealous.

Beatrice (Clea DuVall) is a housekeeper who suffers needlessly as the result of someone else's actions. It's not fair, any of it. Bad things happen to good people, and good things happen to bad people. And everything affects everything else. "It can never go back to the way it was," Walker tells his physics class in a lesson on entropy.

Movies in which strangers' lives intersect are difficult to pull off because, almost by definition, they seek to tell too many stories, which means some will not be as fully developed as we would wish. I say that is true particularly of Troy the lawyer's story here. Though McConaughey expertly manifests the man's grief and guilt in his physical person, there ought to be more to it. Instead, the supporting themes of the film are depicted in the secondary stories, weaving a picture that looks best when viewed from a distance, rather than by picking out the individual elements.

The tone is fairly melancholy, though not joyless. The film makes you reflect and makes you watch, but it rarely makes you laugh.

Alan Arkin's performance as Gene is magnificent, his seething jealousy boiling hotter and faster but always being forced below the surface. It is always nice to see Amy Irving, too, though her role is limited. John Turturro continues to prove he is one of our best character actors as the hopeless academic.

Basically, our happiness is often left to random acts of strangers who have no idea their behavior will affect us, because they're too busy worrying about how someone ELSE'S actions have impacted THEM. Physics, as we are told, is an exact science. Life is not.